It has been proposed to make halogen cycle incandescent lamps with connecting leads passing through the glass housing, made of molybdenum or tungsten wire. The high temperature of operation of halogen lamps requires the use of quartz glass or hard glass for the lamp housing. The internal connections of the lamp lead-in wires are usually much smaller or thinner than the external connections of the lamp leads if the external connections are to be used at the same time as connecting pins which can be fitted into a socket formed as a connector with spring clips to make electrical contact with the projecting lead-in wires. In order to connect the externally projecting pins and the internally projecting lead-in elements, welding processes have been used. It has been found that if molybdenum lead-in wires or tungsten lead-in wires are welded together, regions of brittle zones may form at the weld points. This detracts from the mechanical strength of the lead-in wires as well as of the lamp as a whole.